Andre Saine gave a talk at the NCH summer school on the principles of homeopathy. It's an interesting presentation of the subject, though obviously not the last word on it. Here are my notes from his talk.
Homeopathy was defined by Hahnemann and must be practiced according to the principles he described. These are:
1. The law of similars, or similia similibus curantur. The sick are most easily, mildly, and permanently cured by the most similar medicine. For example, podophylum causes and cures diarrhea. This principle is established by treatment and not hypothesis. Homeopathy is the only system of medicine where all treatment is lawful.
2. The fundamental, intrinsic cause of real disease is the untunement of the vital force.
3. The change and morbid condition of function of tissue and organs in real disease are the result of dynamic disturbance and are not the cause of disease.
4. The totality of the symptoms, objective and subjective, as well as etiologic factors and characteristics of the person are the sole indication for choice of the remedy. Medicine cannot be based on opinion or hypothesis. Medicine has usually been deductive, not inductive.
5. By constant individualization we treat the patient and not the disease.
6. In order to secure the best practical results, medicines must be administered singly. Without systematic application of the inductive method, you will not get far.
7. The only remedy that merits preference is always the one that is most similar to the characteristic symptoms of the disease. There are only degrees of similarity, not an absolute. If the the degree of similarity is high enough, the result will be good. This is explained in aphorisms 154 and 258 of the Organon.
8. This single remedy will be prescribed for its dynamic property in an optimal posology. For example, salt (natrum muriaticum) in its crude form is not a remedy. It must be potentized to be effective.
9. To ascertain the sick making properties of medicine, they must first be proven in the healthy and second be confirmed in curing the sick. Only remedies that have been proven and confirmed should be used. The doctrine of signatures is deductive and is not part of homeopathy. We cannot base a practice that determines life or death on a hypothesis.
10. Like prevents like. A remedy that is given in advance of illness will prevent the disease it will cure. This is homeopathic prophylaxis.